>Google seems to not like any "raw" access to their services i.e. anything outside their attempt at a "walled garden". Here's a link explaining what another app needs to go through to get integration with Google SMTP to work: https://kb.synology.com/en-global/SRM/tutorial/How_to_use_Gmail_SMTP_server_to_send_emails_for_SRM . I'm not sure sending via CDO would support everything needed for that to work.

Some 15 years ago I remember using gmail's SMTP from home, i.e. sending emails from my mozilla/netscape/whatever, and the instructions were simple, no walls, just the server address, how to set the password, which port, done. It worked for years... probably all those years while they stayed with the „do no evil“ mantra.

>My guess is the only way to know is to test. And test again 3 months from now: Google is renowned for everything being beta, and for changing how things like this might work without notice.

Ah, no, it's not a beta. I'd know, Beta is my wife :). It's the simple will to change the rules on a whim, because they have this feeling that they're the only game in town. Remember Panoramio? It was a cool idea and I loved the site, I contributed about 800 photos with locations (found them all manually!). When Google bought it, I stayed through several changes of rules, even through the rough contradiction of not really owning the copyright and seeing how photos I made are used for house sellers' advertising (not only for free, but without much notification - had I not checked where my pics were linked from, I wouldn't have known). When they changed the rules the fourth time, I just had enough, and decided to write off my investment of time and effort, and forfeit the 750.000 image views I had by then, by adding two more hours of the said effort - I removed all my pictures, one by one (they didn't have an option to do more at a time). This was in july 2012.

Didn't have any such thing with M$, though, because about them I knew they couldn't be trusted (since 1987!). Unfortunately, I still live with Skype, because it's not only my investment of time and effort, it's dozen other people with whom I want to stay in touch. So I had to go, over the last 14 years, through dozens of versions, where each major upgrade _removed_ something that existed previously. From a simple and very versatile p2p communication app, M$ turned it into complicated internally but simplified to imbecility (gui-wise) client-server based thing.